• Korean Journal of Metals and Materials
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• v.50 no.4
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• pp.271-279
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• 2012

9-12% Cr steels have been used in thermal power plants which repeat start and stop operations. Major factors of fatigue life are temperature, frequency, stress ratio, holding time, microstructure, and environment. Normally, fatigue life decreases at high temperature, low frequency, high stress ratio, and long holding time conditions. A Mod.9Cr-1Mo steel, called G91, was developed at ORNL (Oak Ridge National Laboratory, USA) and was adopted as a high-temperature structural material in the ASME Code in 2004. However, its low-cycle fatigue and fatigue crack growth characteristics have been rarely studied. In this work, we have investigated the low-cycle fatigue crack growth behaviors of G91 steel under various test conditions in terms of temperature and stress ratio. As temperature and stress ratio increase, the crack growth rate becomes faster and striation distance also increases. On the other hand, the number of branch cracks decreases.

• Journal of Animal Science and Technology
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• v.66 no.4
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• pp.645-662
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• 2024

Climate change, driven by the natural process of global warming, is a worldwide issue of significant concern because of its adverse effects on livestock output. The increasing trend of environmental temperature surging has drastically affected meat production and meat product quality, hence result in economic losses for the worldwide livestock business. Due to the increasing greenhouse gas emissions, the situation would get prolonged, and heat exposure-related stress is expected to worsen. Heat exposure causes metabolic and physiological disruptions in livestock. Ruminants and monogastric animals are very sensitive to heat stress due to their rate of metabolism, development, and higher production levels. Before slaughter, intense hot weather triggers muscle glycogen breakdown, producing pale, mushy, and exudative meat with less water-holding capacity. Animals exposed to prolonged high temperatures experience a decrease in their muscle glycogen reserves, producing dry, dark, and complex meat with elevated final pH and increased water-holding capacity. Furthermore, heat stress also causes oxidative stresses, especially secondary metabolites from lipid oxidation, severely affects the functionality of proteins, oxidation of proteins, decreasing shelf life, and food safety by promoting exfoliation and bacterial growth. Addressing the heat-related issues to retain the sustainability of the meat sector is an essential task that deserves an inclusive and comprehensive approach. Considering the intensity of the heat stress effects, this review has been designed primarily to examine the consequences of hot environment temperatures and related stresses on the quality and safety of meat and secondarily focus on cutting edge technology to reduce or alleviate the situational impact.

• Journal of Soil and Groundwater Environment
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• v.19 no.5
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• pp.45-52
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• 2014

Torrefaction and hydrothermal carbonization (HTC) are productive methods to reclaim energy from lignocellulosic biomass. The hydrophobic, homogenized, energy dense and carbon rich solid fuel can be obtain from torrefaction and hydrothermal carbonization. Dead leaves were carbonized in a stainless steel reactor of volume 200 ml with torrefaction ($250-270^{\circ}C$) for 120 minutes and hydrothermal carbonization ($200-250^{\circ}C$) for 30 minutes, with mass yield solid fuel ranging from 57-70% and energy content from 16.81MJ/kg to 22.01 MJ/kg compare to the biomass. The char produced from torrefaction process possess high energy content than hydrothermal carbonization. The highest energy yield of 89.96% was obtained by torrefaction at $250^{\circ}C$. The energy densification ratio fluctuated in between 1.15 to 1.30. On the basis of pore size distribution of the chars, the definition of the International Union of Pure and Applied Chemistry (IUPAC) was used as a classification standard. The pore diameter was ranging within 11.09-19 nm which play important role in water holding capacity in soil. Larger pores can hold water and provide passage for small pores. Therefore, it can be concluded that high pore size char can be obtained my HTC process and high energy content char of 22.01 MJ/Kg with 34.04% increase in energy can be obtain by torrefaction process.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.182-186
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• 2001

An acid forest surface soil as a land farming medium was treated with a water plant alum sludge at 0 to 18%. Indian mustard was grown in the treated soil in a greenhouse for 5 weeks and watered with pH 4 tap water adjusted with a mixed acid (1HNO$_3$: 2H$_2$SO$_4$) during plant growth. Changes in soil property, leachate chemistry, plant growth, and plant uptake of elements by the sludge treatment were determined. The alum sludge treatment increased buffer capacity to acidity, hydraulic conductivity, water holding capacity, and phosphate adsorption of the soil and decreased bulk density and mobility of small particles. The sludge treatment reduced leaching of Al, Mg, K, Na, and root elongation. Plant did uptake less amount of the cations and P but more Ca with the sludge treatment.

• Journal of the Korean Society for Library and Information Science
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• v.27
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• pp.183-214
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• 1994

The purpose of this study is to suggest the schemes to enhance information service functions by the utilization of CD-ROM in medical school libraries. The results of the study are summarized as follows : 1. The selection and evaluation of CD-ROM database are necessary steps in the planning of a CD-ROM. Before the CD-ROM is selected, therefore, medical libraries must make a practical evaluation criteria in important order of information services environment, characteristics of hardware/software, service requirements, price and cost, etc. 2. If possible, CD-ROM MEDLINE must be suited for the information services environment. 3. In case of the popular core journals, full-text CD-ROM should be gradually purchased. 4. In order to reduce the time required from search of bibliographic informations to receipt of original articles, CD-NET system and library holding administration program must be built up and developed. And channel of information search and order/receipt of original article should be varied. 5. Search education program for medical librarians and users should be enforced, and librarians must play an important role in CD-ROM retrieval consultant and intermediator.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.292-297
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• 2014

We synthesized the self-organized nanoporous oxide with potentiostatic anodization of iron foil. The iron oxide nanocomposite (INCs) were fabricated in 1M $Na_2SO_4$ containing 0.5wt% NaF electrolyte holding the potential at 20, 40 and 60 V for 20min, respectively. Field Emmision Scanning Electron Microscopy (FESEM) and X-ray Diffractometer (XRD) were used to evaluate the micromorphology and crystalline structure of INC film. Also, this study was performed to evaluate the fenton reaction using INC film with hydroperoxide for degradation of cyanide dissolved in water. In case of INC-40V in the presence of $H_2O_2$ 3%, the first-order rate constant was found to be $1.7{\times}10^{-2}min^{-1}$, and indicated to be $1.2{\times}10^{-2}min^{-1}$ on commercial hematite powder. This result is shown to be good performance enough to replace the powder type for treatment of wastewater.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.36-50
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• 2009

To suggest the native plants combination for restoration of the dissected sloping area, the plant communities of thirty seven quadrats from five localities of mid-southern part of Korean peninsula were surveyed from 2007 to 2008. Their flora, vegetation structure, and dominant species based on the importance value were investigated. And the soil characters (pH, moisture content, water holding capacity, and organic matter) of each dominant species were analyzed. Also, germination tests were performed to check the stability of restored native plants using seed chips. As a result, 79 native plants were suggested for the dissected sloping area : 20 trees and subtrees for the upper layer, 18 shrubs and vines for the middle layer, and 41 herbs for the lower layer, taken together their flora, dominant species, vegetation structure, soil condition, germination test, flowering period.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.530-538
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• 2009

The Oxic-Settling-Anaerobic (OSA) treatment process, a modified Conventional Activated Sludge (CAS) process, was developed for the purpose of sludge reduction. The insertion of a sludge holding tank into a sludge return line, an anaerobic reactor, forming an OSA process, may provide a cost-effective way of reducing excess sludge production during a process. The OSA process was evaluated for its sludge reduction ability by kinetic parameter and mass balance, with an observed excess sludge reduction of 63.5%, as $P_{X.VSS}$, compared with the conventional activated sludge process.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.115-123
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• 2010

The purpose of this study was to examine the effect of Busan Ocean Industry Expo on ocean related industries and Busan regional economy. The study analyzed the effects of the various projects related to Busan Ocean Industry Expo and answered the question of how to link the effects to development of ocean related industries as well as the economic activation of Busan area. To attain this goal, first of all, this study attempted to analyze status of ocean related industries, characteristics of existing exposition and opinion of enterprises. To maximize the above positive effects of Busan Ocean Industry Expo, several strategic alternatives were suggested.

• Macromolecular Research
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• v.12 no.3
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• pp.251-257
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• 2004

The nature of the nematic liquid crystal (LC) alignment induced by the rubbed polyimide (PI) alignment layers (ALs) and the electro-optical (EO) properties of the LC cells are expected to depend on the chemical and physical features of the PI. By employing five pyromellitic dianhydride (PMDA)-type PIs having different functionalities, we have studied the effects of the PI's structure and chemistry on the alignment characteristics and the cell's EO properties. Increasing the flexibility of the PI increases the pretilt angle and tends to improve the alignment stability. On the other hand, the rigid, fluorinated PI displays poor stability for LCs and induces a less stable/uniform LC alignment and, subsequently, a small pre tilt angle. It also transpired that fluorination of the PI deteriorated the voltage-transmittance characteristics and the voltage holding ratio; increasing the flexibility of the PI structure improves these EO properties. The finding that the qualitative trends for the PI's functionalities are similar for both the alignment and EO properties suggests that the EO properties are closely related to the alignment characteristics, which are determined by short-range interactions between LC and PI molecules.